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showing 10 items of 311 documents
Design and validation of a neuroprosthesis for the treatment of upper limb tremor.
2013
Pathological tremor is the most prevalent movement disorder. In spite of the existence of various treatments for it, tremor poses a functional problem to a large proportion of patients. This paper presents the design and implementation of a novel neuroprosthesis for tremor management. The paper starts by reviewing a series of design criteria that were established after analyzing users needs and the expected functionality of the system. Then, it summarizes the design of the neuroprosthesis, which was built to meet the criteria defined previously. Experimental results with a representative group of 12 patients show that the neuroprosthesis provided significant (p <; 0.001) and systematic trem…
Impact of Corneoscleral Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconic Eyes
2019
Objective To analyze the changes in corneal biomechanical parameters of keratoconic eyes with and without intracorneal ring segment (ICRS) implants after 1 year of corneoscleral contact lens (CScL) wear. Methods Seventy-four eyes of 74 patients were divided into three groups: healthy subjects (29 eyes, control group), and 2 groups of subjects with keratoconic eyes (one group of 20 eyes with ICRS implants and one of 25 eyes without them), which were fitted with CScL. Corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc) were evaluated before fitting CScL and after 1 year of CScL wear. In addition, endothelial cell count (ECC) and centr…
A new approach based on Machine Learning for predicting corneal curvature (K1) and astigmatism in patients with keratoconus after intracorneal ring i…
2014
Keratoconus (KC) is the most common type of corneal ectasia. A corneal transplantation was the treatment of choice until the last decade. However, intra-corneal ring implantation has become more and more common, and it is commonly used to treat KC thus avoiding a corneal transplantation. This work proposes a new approach based on Machine Learning to predict the vision gain of KC patients after ring implantation. That vision gain is assessed by means of the corneal curvature and the astigmatism. Different models were proposed; the best results were achieved by an artificial neural network based on the Multilayer Perceptron. The error provided by the best model was 0.97D of corneal curvature …
Intrastromal corneal ring segment implantation in paracentral keratoconus with coincident topographic and coma axis.
2012
To evaluate the efficacy, predictability, and safety of implantation of Ferrara-type intrastromal corneal ring segments (ICRS) for refractive correction of paracentral keratoconus.Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Cohort study.Snellen uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors were recorded before and 6 months after ICRS implantation for keratoconus. The tunnels for ICRS implantation were created with a femtosecond laser. The power vector and the Alpins method were used to analyze postoperative refractive outcomes.The study evaluated 56 eyes of 49 patients. The mean UDVA was 0.17 ± 0.14 (SD) preoperatively and 0.41 …
A comparison of the triceps surae and residual muscle moments at the ankle during cycling.
1991
The rigid linked system model and principles of inverse dynamics have been widely used to calculate residual muscle moments during various activities. EMG driven models and optimization algorithms have also been presented in the literature in efforts to estimate skeletal muscle forces and evaluate their possible contribution to the residual muscle moment. Additionally, skeletal muscle-tendon forces have been measured, directly, in both animals and humans. The purpose of this investigation was to calculate the moment produced by the triceps surae muscles and compare it to the residual muscle moment at the ankle during cycling at three power outputs (90, 180 and 270 W). Inferences were made r…
The effect of surgical suture material on osteoclast generation and implant-loosening
2020
Background: Implant loosening - either infectious or aseptic- is a still a major complication in the field of orthopaedic surgery. In both cases, a pro-inflammatory peri-prosthetic environment is generated by the immune system - either triggered by bacteria or by implant wear particles - which leads to osteoclast differentiation and osteolysis. Since infectious cases in particular often require multiple revision surgeries, we wondered whether commonly used surgical suture material may also activate the immune system and thus contribute to loss of bone substance by generation of osteoclasts. Methods: Tissue samples from patients suffering from infectious implant loosening were collected intr…
Clinical analysis following lumbar interspinous devices implant: where we are and where we go
2014
Objectives:We present our experience with patients treated with interspinous devices who are affected by neurogenic intermittent claudication (NIC) or lumbar disc herniation (LDH) where the interspinous system has been inserted following microdiscectomy.Study design:Retrospective study.Methods:This study included patients (n=100) with NIC secondary to lumbar spinal stenosis (group 1), and patients (n=100) with LDH (group 2) in whom the interspinous device has been implanted following radicular decompression in a period spanning 6 years. The latter have been compared with a homogenous group of patients (n=100) where no interspinous system has been implanted following microdiscectomy (group 3…
Reanimation of the Paralyzed Human Larynx With an Implantable Electrical Stimulation Device
2003
Objectives/Hypothesis Electrical stimulation of the posterior cricoarytenoid muscle, when paced with inspiration, offers a physiological approach to restore ventilation in bilateral laryngeal paralysis without any of the disadvantages associated with conventional treatment. Study Design A prospective study of six patients. Methods The patients were successfully implanted with an Itrel II stimulator (Medtronic, Inc). In postoperative sessions, stimulated vocal fold abduction, patient ventilation, and voice were assessed and compared with preoperative values. Results The optimum stimulus paradigm was a 1- to 2-second train of 1-millisecond pulses delivered at a frequency of 30 to 40 Hz and am…
Modified fixation free plug technique using a new 3D multilamellar implant for inguinal hernia repair: a retrospective study of a single operator cas…
2013
Aim: Implant fixation, mesh shrinkage and poor quality of tissue ingrowth are unresolved issues in modern hernia repair. Many complications reported in the literature such as bleeding, nerve entrapment, hematoma, pain, discomfort, and testicular complications, are considered to be a direct results of implant fixation. This article describes the outcomes of a procedure carried out using a handcrafted implant that addresses the issues consequent to point fixation. Methods: This was a retrospective study on the short, medium and long-term results of placing a-modified, fixation free three-dimensional polypropylene implant in 61 patients who underwent inguinal hernia repair using a novel delive…
New mesh shape and improved implantation procedure to simplify and standardize open ventral hernia repair: a preliminary report.
2010
Introduction Issues in ventral hernia repair are represented by the need for mesh fixation and how to assure a sufficient mesh overlap of the defect. Aiming to resolve these problems, this study describes a modified technique for ventral and incisional hernia repair based upon a newly developed mesh with a special design. This new type of implant allows broader coverage of the abdominal wall and results in tension- and fixation-free repair. Materials and methods A unique geometrically shaped mesh consisting of a large central body and radiating arms was used to repair ventral or incisional hernia. The mesh was intended not to be point-fixated. The friction of the straps passing through the …